Vodacom *********** customer service

I have change my surname more than once at Vodacom, years ago. All legit documents brought personally to a Vodacom branch in Westgate Roodepoort, scanned to Vodacom head office and so on. I still get calls from Vodacom to date with my previous surname and on Vodacom's system also not fixed. If my Surname does not get change by end off day 28 June 2019 this month I will cancel all my contracts with Vodacom. Vodacom's customer service is pathetic and I don't get any joy. I have been a customer for many years at Vodacom and feel this is getting ridicules with *********** people that does not know how to change a surname.